From a health promotion perspective, schools are ideal settings for the promotion of physical activity since virtually all children and youth can be reached. Physical education is mandatory in many countries and offers unique opportunities for the promotion of physical activity among children and youth. However, since physical education represents a rather small proportion of the total waking hours among children and youth, it is important to determine the influence of physical education on daily physical activity among children and youth. While studies indicate that children and youth are physically active during physical education and that interventions might increase physical activity even further, the individual contribution of physical education to daily physical activity appears promising but not conclusive.